Veggie mushroom burger An irresistible vegetarian mushroom burger filled with melty mozzarella and slathered in homemade tomato relish. This is designed to be a low cost recipe. Ingredients For the relish 1 tbsp olive oil 1 onion, finely diced salt and pepper 1 garlic clove, crushed 200g/7oz tinned tomatoes 1 tbsp white wine vinegar For the onions 25g/1oz butter 2 onions, finely sliced For the rest of the burger 4 large flat mushrooms, stalk trimmed so it doesn’t come above the edge of the mushroom 1 tbsp olive oil 1 ball mozzarella 4 burger buns, sliced in half Recipe tips Method Preheat the oven to 180C/160C Fan/Gas 4. For the relish, heat a small frying pan over a medium heat and add the olive oil. Fry the onion and a pinch of salt in the oil for 4-5 minutes, or until the onion is soft. Add the garlic and cook for two minutes, then stir in the tomatoes and the vinegar. Gently simmer for five minutes, or until the mixture has thickened to a relish consistency. Taste and adjust the